I'm currently reading May We Be Forgiven
, by A. M. Homes. She doesn't use chapters at all, relying on section breaks all of the way through the 480-page novel. The sections vary in length from one line to five pages.
So far as I can see, there's no good reason for using this method, for even when her protagonist indulges in a stream of consciousness episode of internal dialogue it's not always discrete from what other characters say and do.
As a reader, it's weirdly disorientating not to have chapters. I can't decide that I'll read until the end of Chapter 11 before putting the book down but have to read until an incident or particular day is over.
As a writer, I'm a big fan of section breaks, as it allows me to describe separate events within a chapter that may, or may not, be linked. I've only even used a maximum of three section breaks in any one chapter.
When publishing an ebook, sites such as Smashwords love you to have a well-organised Table of Contents, to enable Kindle readers to readily return to where they left the action. I wonder what they'd make of a novel that was all section breaks....